Update on indoor allergens and their impact on pediatric asthma

Abstract

Objective: In recent decades, many indoor allergens have been identified, including dust mite, cat, dog, mouse, cockroach, and indoor molds, which have important health effects particularly in sensitized individuals with asthma. This review aims to update our understanding regarding the extent of these exposures in the indoor environment, review strategies for reducing their levels in the environment, and highlight innovative recent trials targeting these exposures and their impact on pediatric asthma morbidity.

Data sources: Recent practice parameter updates on indoor allergen exposures, seminal studies, and recent peer-reviewed journal articles are referenced.

Study selections: This review cites recent cohort studies of well-characterized pediatric patients with asthma and innovative randomized controlled trials evaluating exposure to environmental allergens, interventions to limit these exposures, and their outcomes.

Results: Links between indoor aeroallergen exposures and health outcomes have been well established. However, only some allergen reduction interventions have been successful in improving health outcomes.

Conclusion: There are many complicating factors involved in allergic exposures and health outcomes. The interplay between patient genetic factors, indoor allergic triggers, airborne irritants and pollutants, and microbial exposures complicates the study of indoor allergen exposures and their impact on asthma morbidity.

Figure 1:

Common indoor allergens and interventions for reduction of indoor allergen exposure. Evidence level for effectiveness in reducing allergen noted in parenthesis following recommended intervention. Evidence level graded when available for the intervention according to the Scottish Intercollegiate Guidelines Network recommendations: Ia, evidence from meta-analysis of RCTs; Ib, evidence from at least one RCT; IIa, evidence from well-designed controlled study without randomization; IIb, evidence from at least one other type of well-designed quasi-experimental study; III Evidence from well-designed descriptive studies; IV, Evidence obtained from expert committee reports and/or clinical experience of respected authorities.